ZURICH, SWITZERLAND—Paleopathologist Frank Ruhli of the University of Zurich used a CT scanner to examine the teeth of Ötzi, the Neolithic man whose frozen mummy was discovered in the Italian Alps in 1991. “It’s surprising how bad condition he is in. We have the whole range of disease pathologies you can imagine,” said Ruhli. Ötzi’s diet, rich in milled grains, would have abraded the surface of his teeth and gums, eventually exposing the bone and loosening his teeth. He suffered from severe wear of his tooth enamel, several cavities, and severe gum disease. His right front incisor was also damaged, probably in a fight or an accident.